Releasable backstop for conveyor rollers

ABSTRACT

An internally powered conveyor roller, of the type used for driving a conveyor one direction, and for preventing movement in opposite direction and having a drive roller for driving the conveyor medium, an internal drive motor for driving the roller, a one-way rotation device permitting rotation of the roller in one direction, and for preventing rotation in the opposite direction, and the one way rotation means being moveable between engaged and disengaged positions, and when in the disengaged position, being inoperative to prevent reverse rotation of the roller.

TECHNICAL FIELD

[0001] The invention relates to rollers for conveyor systems, and inparticular to an internal drive conveyor roller system having abackstop, or anti-reverse movement check, and in which the backstop canbe released in certain circumstances to allow reverse movement of theconveyor system.

BACKGROUND ART

[0002] Many conveyors are designed around a systems of conveyor chainsor mesh screens, or in some cases, conveyor belts. These conveyor“media” may be supported on simple shafts on which may be mountedvarious forms of sprockets, or drive means for supporting the conveyormedia. More advanced conveyor systems are known using enclosed andsealed drive rollers with the drive motors contained inside the rollersthemselves.

[0003] The use of internal drives for the conveyor rollers isparticularly advantageous in many situations where conveyors arerequired. In these systems the rollers usually carry a conveyor belt orconveyor chains or some similar supports, which run over the rollers andwhich carry load items or product to be conveyed.

[0004] Food product conveyors are a typical example where such internaldrive rollers are used, although the invention is not restricted to suchuse. The roller drives are located inside the drive rollers themselves,and are sealed, and are not liable to contamination from the productbeing carried, and furthermore the product itself will not becontaminated by the drive system, which may require lubricants, andwhich may accumulate dirt, if exposed.

[0005] In many situations, parts of the conveyor system will run level,but at other locations the conveyor system runs at an angle. In theselocations the conveyor belts or chains are required to run along anuphill incline. In these cases if the incline conveyor is halted for anyreason, the weight of product will tend to cause the incline conveyor torun in reverse. If this is allowed to occur, the product will movebackwards and will accumulate at the bottom of the incline conveyor, andprobably collect at the leading end of the preceding level portion ofthe conveyor system.

[0006] This will in most cases damage the load items or product and willcause downtime on the system while the problem is corrected. In order toprevent this from happening it is known to provide the incline conveyor,in one of the rollers, with what is known as a “backstop”. This issimply a form of dog clutch or brake, which allows rotation in theforward direction, ie with the conveyor running up the incline, butprevents rotation in the reverse direction. By the use of this backstopdevice reverse movement of the incline conveyor cannot take place. Ifthe conveyor system stops for any reason, the incline conveyor willsimply remain stationary, without moving or slipping backwards.

[0007] While this device solves the problem of unwanted reversemovement, there are some cases where the operator of the conveyor systemwill want to override the backstop. The operator for whatever reasonwishes to permit the conveyor to move in reverse. However the effect ofthe backstop is to prevent this altogether.

[0008] Clearly therefor in order to satisfy customer requirements it isdesirable to provide a backstop which is normally engaged, and whichthus prevents reverse movement, but which can be disengaged by theoperator, in situations where he wishes the conveyor to move in reverse.

DISCLOSURE OF THE INVENTION

[0009] With a view to satisfying the foregoing requirements theinvention s provides an internally-powered conveyor roller, of the typeused for driving a conveyor medium in a first predetermined direction,and for preventing movement in a second direction opposite to the firstand having roller means for carrying the conveyor medium, internal drivemeans for driving the roller means, one-way rotation means forpermitting rotation of said roller means in one direction, and forpreventing rotation in the opposite direction, and, said one wayrotation means being moveable between engaged and disengaged positions,and when in said disengaged position, being inoperative to preventreverse rotation of said roller means.

[0010] The invention further provides an internally powered conveyorroller having the foregoing advantages and wherein said roller meansincludes a cylindrical drum, and end discs closing each end of the drum,and motor means located within said drum.

[0011] The invention further provides an internally powered conveyorroller having the foregoing advantages and wherein said end discsincorporate hubs and mounting shafts extending through said hubs formounting said roller means in position in a conveyor system.

[0012] The invention further provides an internally powered conveyorroller having the foregoing advantages and wherein said motor meansdrives said drum through reduction gear means within said drum.

[0013] The invention further provides an internally powered conveyorroller having the foregoing advantages and wherein said one-way rotationmeans includes a body member engageable with said motor drive means forcontrolling one way rotation thereof, and means for moving said bodymember into a disengaged position wherein said motor is free to rotatein either direction.

[0014] The invention further provides an internally powered conveyorroller having the foregoing advantages and wherein said body member isenclosed within a ring member and including rod means connected to saidring member and extending therefrom axially of said drum and throughsaid disc member at one end of said drum, and means for operating saidrod member to draw the same outwardly or to return it inwardly, therebydiseasing said body member from said motor shaft upon outward movementand re-engaging said body member with said motor shaft upon returnmovement of said rod member.

[0015] The invention further provides an internally powered conveyorroller having the foregoing advantages and wherein said body member isformed with spaced apart roll recesses and rolls moveably located inrespective recesses, and said rolls moving inwardly within said recessesupon rotation in one direction, and said rolls moving outwardly of saidrecesses upon reverse movement, thereby contacting and binding againstsaid ring member and preventing further such reverse movement.

[0016] The invention further provides an internally powered conveyorroller having the foregoing advantages and wherein said motor shaft isformed with a splined end portion and wherein said body member is formedwith an internally splined recess for receiving said splined end, whenin said engaged position.

[0017] The invention further provides an internally powered conveyorroller having the foregoing advantages and wherein a support shaft issecured to said disc member closing said drum at one end thereof, andsaid shaft member defining a hollow interior and wherein said rod memberis located within said hollow shaft member.

[0018] The invention further provides an internally powered conveyorroller having the foregoing advantages and wherein said rod member isprovided with means for grasping the outwardly extending portion of saidrod member and manually drawing said rod member outwardly as aforesaid.

[0019] The various features of novelty which characterize the inventionare pointed out with more particularity in the claims annexed to andforming a part of this disclosure. For a better understanding of theinvention, its operating advantages and specific objects attained by itsuse, reference should be had to the accompanying drawings anddescriptive matter in which there are illustrated and describedpreferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020]FIG. 1 is a schematic sectional side elevation, partially cut awayand shortened, of a conveyor roller, with an internal drive, andillustrating one embodiment of the invention in the form of a releasablebackstop;

[0021]FIG. 2 is an enlarged sectional side elevation of a portion of theconveyor roller of FIG. 1 showing the releasable backstop in its engagedposition;

[0022]FIG. 3 is a sectional side elevation corresponding to FIG. 2 butshowing the releasable backstop in its disengaged position, and,

[0023]FIG. 4 is a section along line 44 of FIG. 3.

MODES OF CARRYING OUT THE INVENTION

[0024] As explained above the invention finds its application as part ofa conveyor system. Such conveyors may be found in many differentapplications. One significant aspect of such conveyor systems is thatthey are designed around conveyor rollers which carry the conveyormedium. This may be a belt, or a series of conveyor supports such aschains. The drive rollers in such a conveyor system which are powered soas to drive the conveyor medium are internally driven. That is to saythe drive rollers contain within the roller drum, the drive motor and inmost cases, reduction gears. The entire drum is sealed so that alllubricants are retained within the interior of the drum, and all outsidecontaminants are excluded. The only connection to the exterior isprovided by support shafts extending from each end of the roller, andelectrical connections by which power is supplied to the drive motorwithin the drum.

[0025] Clearly not all rollers in such a system are power driven. Someare idle rollers which function simply to support the conveyor medium.However in this case also the rollers are sealed so that there is nocontamination.

[0026] Where the conveyor system is required to elevate the load items,referred to herein as “product”, then a length of the conveyor isprovided which runs at an angle, on an incline. Conveyor segments ateach end of the incline will usually be level.

[0027] As explained in such incline sections the powered roller isprovided with a backstop, or anti-rollback device. This functions toprevent reverse movement of the inclined conveyor, if the conveyor isstopped for any reason.

[0028] The invention is directed to the provision of such a backstopdevice which can be manually disengaged, or re-engaged as required bythe operator.

[0029] Referring to FIG. 1 the invention is illustrated in the form of apowered roller 10. It is understood that such roller 10 is to be locatedsomewhere in a conveyor system where the conveyor medium is inclined.Roller 10 would thus normally be supported on a framework (not shown) ofa type well known in the art and requiring no description. A conveyormedium such as a belt or chains or the like (not shown) would run aroundroller 10 in a manner well known in the art.

[0030] Idle rollers (not shown) would also be provided so that theconveyor medium runs around a continuous path in a manner well known,and is supported in a manner adequate for the product being carried.Usually the driven roller will be at one end of the conveyor segment,either the lower or upper end.

[0031] The roller 10 is provided with a cylindrical hollow drum 12,which is supported at each end by respective left and right end discs 14and 16. Left disc 14 has a central hub 18 supporting a bearing 20 andright disc 14 has a hub 22 supporting a bearing 24.

[0032] An electrical drive motor is indicated generally as 26. It ismounted within the interior of drum 12 and is supported between a leftend housing 28 and a right end housing 30. The drive housings and motorare known per se and are held together as a unit by threaded rods 32. Adrive shaft 34 extends through motor 30 and through both left and righthousings 28 and 30.

[0033] The left end of shaft 34 is formed with shaft gear teeth 36. Areduction gear 38 is mounted in left end housing 28 and is driven byshaft teeth 36.

[0034] Gear 38 has a gear shaft 40, formed with reduction teeth 42.Teeth 42 engage a drum drive gear 44, formed on left hub 18 of the leftend disc 16. Drum gear has external teeth 46. The location and number ofteeth 46 can vary from one application to another. While the teeth 46are shown on an inner portion of hub 18, which is in effect in theposition of a sun gear in an epicyclic system, it will be appreciatedthat hub 18 can be formed with a much larger gear ring (not shown)having internal teeth, which would be in effect in the position of thering gear of an epicyclic system. Such a ring gear would have many moreteeth, than the central sun-type gear shown, and so a greater speedreduction would be obtained.

[0035] A left roller mounting shaft 48 is received in the left hub 18,thus permitting the left end of the roller to be mounted and secured ona suitable frame or support, at a desired location in the conveyorsystem. Electrical connection box 50 is fastened adjacent the left endof roller 10, and wires W extend through the left end mounting shaft(not shown) for supplying power to the motor.

[0036] Attached to the right motor housing 30 is the backstop housing52. Housing 52 defines an annular flange 54 by which it is bolted toright motor housing 30. Extending from flange 54 is shaft connectorsleeve 56. A right mounting shaft 58 is secured in sleeve 56 and extendsaxially through drum 12 and out through right disc hub 22. Bearings 24in disc hub 22 ride on shaft 58 permitting rotation of drum 12 relativeto shaft 58. Suitable seals are provided to prevent exiting or entry ofcontaminants. Shaft 58 may be secured at the right end of the roller 10to a frame or support, in a suitable location in the conveyor system.

[0037] Within backstop housing 52 a hollow interior chamber 60 isdefined. Right motor housing 30 also defines a recess 62 of similardiameter to chamber 60.

[0038] Motor shaft 34 extends into the interior of recess 62 and isformed with splines 64 on its free end.

[0039] A control rod 66 extends through the hollow interior of rightmounting shaft 58. At its right end rod 66 it extends out of shaft 58and is provided with threaded bore 68. A plug 70 is received in bore 68of rod 66.

[0040] At the inboard or left end of control rod 66 there is a backstopend plate secured to rod 66. A cylindrical ring 74 extends from plate 72is normally received in the recess of 62 of right motor housing 30.

[0041] Dowel pins 75 are located within motor housing 30 around chamber62. Ring 74 has recesses registering with the dowel pins and is thuslocked against rotation relative to housing 30. However ring 74 isslideable along pins 75 out of between recess 60 and 62 for reasons tobe described below. Within ring 74 a one way backstop bearing body 76 islocated. Body 76 is generally annular and carries within it a drive body77 having a central splined recess 78. Recess 78 normally receivessplined end 64 of motor shaft 34. Both body 76, and drive body 77 withits central splined recess 78 are retained together with a key (knownper se) to prevent relative rotation and retained by retaining circlip Cto secure it in its axial location. When the shaft end is received inthe recess 78 in body 76, shaft 34 and body 76 are locked together.

[0042] Body 76 supports a plurality of backstop rolls 80 in respectiveangled recesses 82. A ring 81 surrounds body 76 and rolls 80. Withintheir respective recesses 82 rolls 80 are movable outwardly and inwardlyrelativ to body 76. In their outer position the rolls 80 engage theinner surface of ring 81, and wedge securely against it preventingmovement of body 76 relative to ring 81.

[0043] Ring 81 is itself secured within ring 74, by a press fit.

[0044] Body 76 is retained in ring 74 by a retention circlip 84, leavingbody 76 free to rotate in one direction, within ring 74, as described,without restriction from the circlip 84.

[0045] Ring 74 as explained above, is locked within chamber 62 ofhousing 30 by dowel pins 75. When in their inward positions the rolls 80roll freely, out of wedging contact within ring 81, and permit rotationof body 76 relative to ring 81. In this way when motor 26 is driving itsmotor shaft 34 normally, body 76, which is locked to shaft 34 by splineend 64 in recess 78 is free to rotate within ring 81, in the drivingdirection. Dowel pins 75 will prevent backstop ring 74 and plate 72 fromrotational movement and thus the entire backstop assembly holds themotor shaft 34 against reverse rotation, while allowing forwardrotation.

[0046] However, as stated above the dowel pins 75 allow ring 74 to moveaxially into recesses 62 and back into chamber 60.

[0047] Under normal operation, in the event of a shut down of motor 26for any reason, any attempt by drum 18 to rotate in reverse isprevented. This because body 76 remains locked to shaft 34, and iswedged against reverse rotation by the wedging engagement between rolls80 and ring 81.

[0048] Body 76 and the splined recess 78 are normally engaged with thesplined recess end of 64 motor shaft 34.

[0049] In order to permit manual disengagement, of body 76 from splinedend of shaft 34, the rod 66, on which plate 72 is secured, is slidablewithin shaft 58, as can be seen by comparing FIG. 2 and FIG. 3.

[0050] In order to permit manual sliding of rod 66, the plug 70 isunthreaded and removed.

[0051] A handle member, or knob 86, having a threaded stem 88 isinserted in the threaded recess in the exposed end of shaft 58. Bysimply pulling on the knob 86 the rod is slid axially within shaft 58.This will draw plate 72, ring 74, and body 76 away from splined end 64of shaft 34. The splined end 64 will then no longer be received in thesplined recess 78 of drive body 77, and will not be subject to the oneway reverse checking action of body 76, and rolls 80, described above.

[0052] In the event of the motor shutting down for any reason the motorshaft will now be free to rotate in the reverse direction, and thuspermit the conveyor segment to move in reverse.

[0053] Clearly the body 76 can be re-engaged with splined end 64 bysimply pushing the rod 66 inwardly.

[0054] By this means the conveyor roller is provided with a one waybackstop which normally prevents reverse rotation of the roller, butwhich backstop can be disengaged whenever it is not required, thusproviding the operator of the system with the flexibility of both modesof operation.

[0055] The foregoing is a description of a preferred embodiment of theinvention which is given here by way of example only. The inventionwhich is not to be taken as limited to any of the specific features asdescribed, but comprehends all such variations thereof as come withinthe scope of the appended claims.

1. An internally powered conveyor roller, of the type used for driving a conveyor medium in a first predetermined direction, and for preventing movement in a second direction opposite to the first and comprising; roller means for carrying the conveyor medium; internal drive means for driving the roller means; one-way rotation means for permitting rotation of said roller means in one direction, and for preventing rotation in the opposite direction, and, said one way rotation means being moveable between engaged and disengaged positions, and when in said disengaged position, being inoperative to prevent reverse rotation of said roller means.
 2. An internally powered conveyor roller as claimed in claim 1 and wherein said roller means includes a cylindrical drum, and end discs closing each end of the drum, and motor means located within said drum.
 3. An internally powered conveyor roller as claimed in claim 2 and wherein said end discs incorporate hubs and mounting shafts extending through said hubs for mounting said roller means in position in a conveyor system.
 4. An internally powered conveyor roller as claimed in claim 3 and wherein said motor means drives said drum through reduction gear means within said drum.
 5. An internally powered conveyor roller as claimed in claim 4 wherein said one-way rotation means includes a body member engageable with said motor drive means for controlling one way rotation thereof, and means for moving said body member into a disengaged position wherein said motor is free to rotate in either direction.
 6. An internally powered conveyor roller as claimed in claim 5 wherein said body member is enclosed within a ring member and including rod means connected to said ring member and extending therefrom axially of said drum and through said disc member at one end of said drum, and means for operating said rod member to draw the same outwardly or to return it inwardly, thereby disengaging said body member from said motor shaft upon outward movement and re-engaging said body member with said motor shaft upon return movement of said rod member.
 7. An internally powered conveyor roller as claimed in claim 6 and wherein said body member is formed with spaced apart roll recesses and rolls moveably located in respective recesses, and said rolls moving inwardly within said recesses upon rotation in one direction, and said rolls moving outwardly of said recesses upon reverse movement, thereby contacting and binding against said ring member and preventing further such reverse movement.
 8. An internally powered conveyor roller as claimed in claim 7 and wherein said motor shaft is formed with a splined end portion and wherein said body member is formed with an internally splined recess for receiving said splined end, when in said engaged position.
 9. An internally powered conveyor roller as claimed in claim 8 and wherein a support shaft is secured to said disc member closing said drum at one end thereof, and said shaft member defining a hollow interior and wherein said rod member is located within said hollow shaft member. 10 An internally powered conveyor roller as claimed in claim 9 and wherein said rod member is provided with means for grasping the outwardly extending portion of said rod member and manually drawing said rod member outwardly as aforesaid. 